Mio acts in the brain to control feeding and metabolism in Drosophila. Joseph Manno, Jacqueline McDermott, Justin DiAngelo. Department of Biology, Hofstra Univ, Hempstead, NY.

   After a meal, multiple organs recognize the availability of nutrients and increase the intake of these nutrients and their storage as glycogen and fat. For example, populations of neurons in the brain sense changes in nutrient levels leading to alterations in an animals feeding behavior, amount of food consumed and energy expenditure. However, the molecular mechanisms underlying nutrient sensing and subsequent changes in behavior and metabolism are not fully understood. Our lab has previously shown that Mio, the Drosophila homolog of carbohydrate response element binding protein (ChREBP), functions in the fat body of the fly to control triglyceride storage as well as feeding, suggesting that Mio may act as a nutrient sensor to coordinate food consumption and metabolism. In this study, we characterized the role of Mio in the brain to control feeding and nutrient storage in larvae and adult flies. Lowering Mio levels using RNAi specifically in the central nervous system leads to a decrease in triglycerides in 3rd instar larvae. However, decreasing neural Mio expression in adult flies has little effect on triglycerides and glycogen. Interestingly, depleting Mio in neurons results in increased food consumption in adult flies. These data indicate a role for Mio in neurons to control feeding and metabolism and suggests that Mio may act as a nutrient sensor in the brain to coordinate behavior with nutrient availability.